In most cases, information is related to other information. Information is linked together via links and a link topology structure is formed. The link topology is important information about information. A typical example of important linked systems is WWW. The WWW is a hyperlinked collection. In addition to the textual content of individual pages, the link structure of such collections contains important information which can be helpful to user for searching the required information. For example, consider the significance of a link p→q: With such a link p suggests, or even recommends, that surfers visiting p follow the link and visit q.
Link analysis algorithms try to mine useful information from the link structure and improve the performance of the search engines. Taking advantage of the link structure of the Web, a global “importance” ranking of every web page can be produced.
Unfortunately, most enterprise documents lack links or even do not have link. This makes the information search in the enterprises become difficult.